Some things that surprised me along the way: - Originally I built it only for my friends and family, but they enjoyed this game so much, that I posted it public - Balancing, even for a PvE game, is still hard - I was prepared to get a lot of hate comments since the release, but I mostly get positive feedback and the game seems to help some people dealing with depressions. I know that not everyone will enjoy this game, but I'm happy about everyone who does. - People will go a loooong way to cheat, even in F2P games where they can earn nothing from it. Anti-Cheat is basically impossible, but I'm happy about the global Raid's Anti-Cheat system, which includes 20+ hardening steps in the firebase rules - The internal feedback / ticket system has proven to be a great way (and the main way) for communication with the players
You can play right now without signing up. There's a guest mode. If you want to save progress online, you can log in with Google or email. (But be aware, that cloud syncing is still done manually, there is no auto-syncing!) There are some features that require an account, like viewing the Community Tab and participating in the global raids.
The current version is 3.8.1. I just shipped Season 3 (superhero/villain themed cards) last week with new raid bosses and new features.
Happy to answer questions about the game itself, or what it's like trying to ship something this scope as one person.